This invention relates to an axle assembly for motor vehicles and in particular to an improved structure for a motor vehicle axle assembly which includes an input shaft having a hollow, cylindrical internally-splined stem that is adapted to be connected to an externally-splined shaft of the rear end fitting a driveshaft assembly.
A conventional vehicle drive train assembly includes an engine/transmission assembly that generates rotational power and transmits the rotational power through a driveshaft assembly to an axle assembly. The driveshaft assembly has a front end that is connected to an externally-splined output shaft of the engine/transmission assembly and a rear end that is connected to an externally-splined input shaft of the axle assembly by respective couplings and end fittings. The input shaft of the axle assembly is connected to a drive pinion that meshes with a ring gear of a differential, which is contained within a carrier. The ring gear meshes with a pair of side gears that are connected to a pair of output shafts, typically a pair of axles connected to the wheels of the vehicle. The differential is designed to distribute torque from the input shaft of the axle assembly to the two output shafts, while permitting the two output shafts to rotate at different speeds under certain conditions. When the vehicle is operated in a straight line, the wheels of the vehicle turn at the same speed, and torque is distributed equally by the differential to the two wheels. When the vehicle negotiates a turn, the outside wheel rotates at a somewhat faster speed than the inside wheel. As a result, although torque is continually supplied to both wheels, a somewhat greater amount of torque is supplied to the inside wheel than to the outside wheel.
Although a conventional axle assembly is effective, it has been found that eccentricities in the connection between the rear end fitting of the driveshaft assembly and the input shaft of the axle assembly can cause undesirable noise and vibration. These eccentricities can also make it relatively difficult to create and maintain an adequate seal between the rear end fitting of the driveshaft assembly and the carrier of the axle assembly. It would, therefore, be desirable to provide an improved structure for an axle assembly that reduces undesirable noise and vibration and creates and maintains an adequate seal to promote lubricant retention in the carrier.